Rotary waveguide switch having arcuate waveguides realized by planar faces

Abstract

A waveguide switch with four outputs or inputs (A, B, C, D) normally has one rotor (2) with three passages (3, 4, 5) with which, as appropriate, two waveguide connections can be effected in specific rotor positions. In two switching positions only the central waveguide passage (3) conducts HF signals, whereas in the two other switching positions both curved passages (4, 5) simultaneously conduct HF signals. Whereas the transmission losses in the central passage are low, a very high reflection level has hitherto been obtained in the two curved passages because of the points of inflexion. In order to improve the transmission characteristics, it is proposed to design the curved passages with an elliptical shape. For this, the longitudinal passage (3) is narrowed toward the central point of the rotor, so that sufficient space is provided for the curved portion of the lateral passages. The circular shape of the curved passages (4, 5) can also be approximated by a facet-like shaping of the sidewalls. The points of inflexion (8 or 9) thus created result in only insignificant changes in the transmission characteristics.

We claim: 
     
       1. In a waveguide switch including a housing having an axial bore and at least four waveguide ports extending to a circumference of said axial bore, each of said waveguide port having a rectangular cross section and being arranged in one plane transverse to a longitudinal axis of said bore and at right angles to one another in said plane, a cylindrical rotor disposed in said bore of said housing and provided with three waveguide passages having a corresponding, rectangular cross section so as to produce different waveguide connections between said waveguide ports in certain rotor potions, with one of said waveguide passages in the rotor being configured as a straight central passage and with the other two of said waveguide passages being disposed on respectively opposite sides of said one waveguide passage and with each of said other waveguide passages producing a deflection of the respective waveguide path by π°; the improvement wherein said one waveguide passage is given a cross-sectional taper toward the center of the rotor from each end of said one passage; and each of said other two of said waveguide passages has an at least approximately arcuate shape defined by respective faces of respective longitudinally extending walls of said rotor which delimit said other waveguide passages, each said wall being formed respectively of at least three planar face pieces with bends therebetween to approach said arcuate shape. 
     
     
       2. Waveguide switch according to claim 1, wherein said cross-sectional taper is step-shaped. 
     
     
       3. Waveguide switch according to claim 1, wherein said cross-sectional taper is smooth. 
     
     
       4. Waveguide switch according to claim 1, wherein said rotor includes a circumferential surface having portions which are located between said waveguide passages and which are provided with axially and radially oriented slits to provide cross-tack attentuation for high frequency signals. 
     
     
       5. Waveguide switch according to claim 1, wherein respective interior ones of said faces delimiting said other waveguide passages are each configured of five of said planar face pieces and the respective exterior ones of said faces delimiting said other waveguide passages are each configured of three of said planar face pieces.